Indoor unit of air conditioner

ABSTRACT

An indoor unit of an air conditioner, includes a blower fan disposed within a casing; and a heat exchanger for heat-exchanging between refrigerant and air flowing by the blower fan, said heat exchanger connected to a refrigerant inlet pipe for introducing refrigerant and a refrigerant outlet pipe for discharging a refrigerant, wherein the refrigerant inlet pipe is connected to a side of the heat exchanger, where a flow velocity of the air passing through the heat exchanger is relatively high. Accordingly, efficiency of heat exchange between the indoor air and refrigerant can be improved, and thus cooling and heating efficiency of the indoor air is improved, thereby improving performance of the air conditioner. Also, by reducing the operation time of the air conditioner, power consumption can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an indoor unit of an air conditioner,and particularly, to an indoor unit of an air conditioner capable ofimproving efficiency of heat exchange between refrigerant and air.

2. Description of the Background Art

In general, an air conditioner is an apparatus for maintaining apleasant room temperature by using latent heat of vaporization ofrefrigerant, which is circulated in a refrigerating cycle of acompressor, a heat exchanger, an expansion valve and an evaporator.

The air conditioner performs cooling operation on a room through aseries of processes that refrigerant is compressed by the compressor atup to saturation pressure, the compressed refrigerant is liquefied bythe heat exchanger, the liquefied refrigerant is introduced to theevaporator in a state of being decompressed and expanded by throttlingof the expansion valve, and the introduced refrigerant is heat-exchangedwith ambient air of the evaporator to be evaporated in the evaporator.

Such an air conditioner is divided into an integral type air conditionerand a split type air conditioner according to whether an indoor unit andan outdoor unit are coupled together, and the split type air conditioneris divided into a wall mounted type and a floor standing type accordingto its installation type.

As shown in FIGS. 1 and 2, the indoor unit of the conventional airconditioner includes a casing 110 having an air suction part 112 forsucking the air and an air discharge part 114 positioned at an upperportion, for discharging the air; a blower fan 120 installed inside thecasing 110, for sucking and discharging the air; and a indoor heatexchanger 130 installed inside the casing 110, for heat-exchanging theair flowing inside the casing 110 with a refrigerant.

The indoor heat exchanger 130 is an A-coil heat exchanger type having apair of slabs 131 and 132. As for the slabs 131 and 132, a plurality oftubes 133 through which refrigerant flows are respectively installed inthe slabs, and the slabs 131 and 132 are at a predetermined angle astheir upper ends of the slabs are coupled together and their lower endsare apart from each other.

A refrigerant inlet 136 connected to a refrigerant inlet pipe 134 forintroducing refrigerant from an outdoor unit (not shown), thus tointroduce the refrigerant to the tubes 133 of the slabs 131 and 132 isinstalled at a lower end of each slab 131 and 132. And a refrigerantoutlet 137 connected to a refrigerant outlet pipe 135 for dischargingrefrigerant to an outdoor unit, thus to discharge the refrigerant havingpassed through the tubes 133 toward the outdoor unit is installed at anupper end of each slab 131 and 132.

In addition, a thermostatic expansion valve (TXV) 138 for controlling aflow of refrigerant according to a temperature of a refrigerant and arefrigerant distributor 139 for distributing refrigerant toward eachrefrigerant inlet 136 are installed at the refrigerant inlet pipe 134.

Meanwhile, the blower fan 120 is disposed under the indoor heatexchanger 130, and an outlet of the blower fan 120 is arranged toward anupper side of the indoor heat exchanger 130.

By such a structure, the refrigerant repetitively undergoes a series ofprocesses that refrigerant compressed by the compressor emits heat toambient air while passing through an outdoor heat exchanger, to therebybe changed into a high temperature and high pressure liquefiedrefrigerant, the high temperature and high pressure liquefiedrefrigerant is decompressed and expanded by being introduced to the TXV138 through the refrigerant inlet pipe 134, the refrigerant havingpassed through the TXV 138 is introduced to the indoor heat exchanger130 through the refrigerant inlet 136, is evaporated by absorbingambient heat, to thereby be a low temperature and low pressure gaseousrefrigerant, and then is sucked again to the compressor through therefrigerant outlet 137 and the refrigerant outlet pipe 135.

At this time, the blower fan 120 is driven theretogether. According tothis, the indoor air is introduced into the casing 110 through the airsuction part 112, is heat-exchanged by coming in contact with the indoorheat exchanger 130, and is discharged to the outside of the casing 110through the air discharge part 114.

And, in heating operation, refrigerant moves in reverse order of thefreezing cycle, and the indoor heat exchanger 130 functions as acondenser, so that a room is heated.

Meanwhile, because the blower fan 120 is disposed under the indoor heatexchanger 130, air sent from the blower fan 120 flows from the lowerends of the slabs 131 and 132 toward the upper ends. Here, a passage ofthe air flowing from the blower fan 120 becomes narrower from a lowerside toward an upper side because a distance between the slabs 131 and132 gets longer from their upper ends toward the lower ends.Accordingly, a flow velocity of air flowing from the blower fan 120 ishigher at the upper end sides of the slabs 131 and 132 rather than attheir lower end sides of the slabs 131 and 132.

However, in the indoor unit of the conventional air conditioner havingsuch a structure, refrigerant passing through the upper ends of theslabs 131 and 132 has undesirably already overheated to some degree byheat-exchange with the air because the refrigerant is introduced to therefrigerant inlets 136 of the lower ends of the slabs 131 and 132,passes through the tubes 133, and is discharged to the refrigerantoutlets 137 of the upper ends of the slabs 131 and 132. Accordingly,even though a flow velocity of the air passing the upper end of the slab131 and 132 is higher than that of the air passing the lower end of theslab 131 and 132, heat exchange between air and refrigerant cannot beeffectively performed at the upper ends of the slabs 131 and 132.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide an airconditioner capable of improving efficiency of heat exchange between arefrigerant and air and improving cooling and heating efficiency byinstalling a refrigerant inlet for introducing refrigerant to an indoorexchanger at a position where a flow velocity of air is higher than aposition of a refrigerant outlet.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided an indoor unit of an air conditioner, comprising ablower fan disposed within a casing; and a heat exchanger forheat-exchanging between refrigerant and air flowing by the blower fan ,said heat exchanger connected to a refrigerant inlet pipe forintroducing refrigerant and a refrigerant outlet pipe for dischargingrefrigerant, wherein the refrigerant inlet pipe is connected to a sideof the heat exchanger, where a flow velocity of the air passing throughthe heat exchanger is relatively high.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute aunit of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is an exploded perspective view showing an indoor unit of aconventional air conditioner;

FIG. 2 is a schematic view showing an indoor unit of the conventionalair conditioner;

FIG. 3 is an exploded perspective view showing an indoor unit of an airconditioner in accordance with the present invention; and

FIGS. 4 and 5 are schematic views showing an indoor unit of the airconditioner in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

As shown in FIGS. 3 and 4, an outdoor unit of an air conditioner inaccordance with the present invention includes a casing 10 having an airsuction part 12 positioned at a front side of the casing 10 and an airdischarge part 14 positioned at an upper side of the casing 10; a blowerfan 20 installed within the casing 10, for sucking and discharging air;and an indoor heat exchanger 30 installed inside the casing 10 andheat-exchanging between refrigerant and air flowing by the blower fan 20and passing through the indoor heat exchanger 30.

The indoor heat exchanger 30 is an A-coil heat exchanger type having apair of slabs 31 and 32. As for the slabs 31 and 32, a plurality oftubes 33 respectively connected to an outdoor unit, a refrigerant inletpipe 32 and a refrigerant outlet pipe 35 thus to flow a refrigeranttherethrough are respectively installed therein, and the slabs 31 and 32are arranged to be at a predetermined angle as upper ends of the slabs31 and 32 are coupled to each other and their lower ends are apart fromeach other.

Here, a flow velocity of the air is higher at the upper ends where theslabs 31 and 32 are coupled together rather than at the lower ends.Therefore, to improve efficiency of heat-exchange between refrigerantpassing through the slabs 31 and 32 and air, a refrigerant inlet 36connected to the refrigerant inlet pipe 34 is installed at each upperend of the slabs 31 and 32, and a refrigerant outlet 37 connected to therefrigerant outlet pipe 35 is installed at each lower end of the slabs31 and 32.

Also, a thermostatic expansion valve (TXV) 38 for controlling a flow ofa refrigerant according to a temperature of refrigerant; and arefrigerant distributor 39 for distributing refrigerant toward eachrefrigerant inlet 36 are installed at the refrigerant inlet pipe 34.

Meanwhile, the blower fan 20 is disposed adjacent to a lower side of theindoor heat exchange 30 in comparison with its adjacency to an upperside of the indoor heat exchanger 30, and an outlet of the blower fan 20is installed toward the upper side of the indoor heat exchanger 30. Sucha blower fan 20 is formed by coupling a turbo fan, a kind of acentrifugal fan, to a fan motor (not shown) so as to suck, pressurizeand discharge the indoor air.

The refrigerant distributor 39 equally distributes refrigerant to eachrefrigerant inlet 36, and pipes coupled to the refrigerant distributor39 preferably have a vertical length of at least about 5 cm or longer.

Meanwhile, as shown in FIG. 5, preferably, a four way valve connected tothe refrigerant inlet pipe 34 and the refrigerant outlet pipe 35, forconverting circulation of refrigerant discharged from the compressoraccording to a heating cycle or a cooling cycle is installed, so thatthe indoor unit in accordance with the present invention can carry outnot only the cooling operation but also the heating operation.

By such a structure, the refrigerant repetitively undergoes a series ofprocesses that refrigerant compressed by driving of the compressor emitsheat to ambient air while passing through an outdoor heat exchanger, tothereby be changed into a high temperature high pressure liquefiedrefrigerant, the high temperature and high pressure liquefiedrefrigerant is decompressed and expanded by being introduced to the TXV38 through the refrigerant inlet pipe 34, the refrigerant having passedthrough the TXV 38 is introduced to the indoor heat exchanger 30 throughthe refrigerant inlet 36, is evaporated by absorbing ambient heat, tothereby be a low temperature and lower pressure gaseous refrigerant, andthen is sucked again to the compressor through the refrigerant outlet 37and the refrigerant outlet pipe 35.

At this time, the blower fan 20 is driven theretogether. According tothis, the indoor air is introduced into the casing 10 through the airsuction part 12, is heat-exchanged by coming in contact with the indoorheat exchanger 30, and is discharged to the outside of the casing 10through the air discharge part 14.

And, in heating operation, refrigerant moves in reverse order of thefreezing cycle, and the indoor heat exchanger 30 functions as acondenser, so that a room can be heated.

Meanwhile, because the blower fan 20 is disposed under the indoor heatexchanger 30, the air sent from the blower fan 20 moves from the lowerends of the slabs 31 and 32 toward their upper ends. Here, a distancebetween the slabs 31 and 32 gets longer from their upper ends toward thelower ends. Therefore, a passage of the air flowing from the blower fan20 gets narrower from a lower side toward an upper side. Accordingly, aflow velocity of the air flowing from the blower fan 20 is higher at theupper ends of the slabs 31 and 32 rather than at the lower ends.

At this time, because the refrigerant inlet pipe 34 is connected to theupper end of the slab 31 and 32, the refrigerant is introduced to theupper end of the slab 31 and 32, where a flow velocity of the air ishigh, and is heat-exchanged with the air while flowing along the tube33. And because the refrigerant outlet pipe 35 is connected to the lowerend of the slab 31 and 32, the refrigerant heat-exchanged while passingthrough the tube 33 is discharged from the lower end of the slab 31 and32, where a flow velocity of the air is low. Accordingly, efficiency ofheat exchange between the refrigerant and the air can be remarkablyimproved at a portion where the flow velocity of the air is high.

In the indoor unit of the air conditioner in accordance with the presentinvention, a refrigerant inlet pipe and a refrigerant outlet pipe arerespectively connected to an indoor heat exchanger, so that refrigerantis introduced to a portion where a flow velocity of the air passing theindoor heat exchanger is high and is discharged to a portion where aflow velocity of the air is low. Accordingly, efficiency of the heatexchange between the indoor air and the refrigerant can be improved, andperformance of the air conditioner can be improved by improving heatingand cooling effect for the air. Also, by reducing the operation time ofthe air conditioner, power consumption can be reduced.

The present invention intends to improve efficiency of heat exchangebetween refrigerant and air by introducing the refrigerant to a portionwhere a flow velocity of the air passing a heat exchanger is high anddischarging the refrigerant from a portion where the flow velocity ofthe air is low. Therefore, it should also be understood that theabove-described embodiments are not limited by an indoor unit having anA coil type heat exchanger of the foregoing description, but rather canbe applied to every indoor unit having a heat exchanger in which a flowvelocity of the air is different depending on a portion of the heatexchanger.

1. An indoor unit of an air conditioner, comprising: a blower fandisposed within a casing; and a heat exchanger for heat-exchangingbetween refrigerant and air flowing by the blower fan, said heatexchanger connected to a refrigerant inlet pipe for introducingrefrigerant and a refrigerant outlet pipe for discharging refrigerant,wherein the refrigerant inlet pipe is connected to a side of the heatexchanger, where a flow velocity of the air passing through the heatexchanger is relatively high.
 2. The indoor unit of claim 1, wherein theheat exchanger includes a pair of slabs having therein a tube throughwhich refrigerant passes and disposed to be at a predetermined angletherebetween as ends of the slabs are connected to each other.
 3. Theindoor unit of claim 2, wherein the refrigerant inlet pipe is connectedto each first end of the slabs, where the slabs are connected to eachother.
 4. The indoor unit of claim 3, wherein the refrigerant outletpipe is connected to each second end of the slabs, said second endopposite to the first end of the slab.
 5. The indoor unit of claim 1,wherein the heat exchanger is an A-coil heat exchanger type having apair of slabs disposed to be at a predetermined angle as upper ends ofthe slabs are connected to each other and lower ends of the slabs areapart from each other.
 6. The indoor unit of claim 5, wherein therefrigerant inlet pipe is connected to each upper end of the slabs. 7.The indoor unit of claim 5, wherein the refrigerant outlet pipe isconnected to each lower end of the slabs.
 8. The indoor unit of claim 5,wherein the blower fan is disposed under the heat exchanger.
 9. Theindoor unit of claim 1, wherein a four way valve connected to therefrigerant inlet pipe and the refrigerant outlet pipe, for circulatingrefrigerant according to a heating cycle and a cooling cycle isinstalled.
 10. The indoor unit of claim 9, wherein a thermostaticexpansion valve (TXV) for controlling a flow of refrigerant according toa temperature of a refrigerant is installed at the refrigerant inletpipe.